One of the problems with percussion kits, particularly what may be called a full set of drums is the large volume that is occupied by the drums during storage and transportation.
Collapsible drums are known which collapse so that the drum ends move towards each other. U.S. Pat. No. 1,214,171 shows such a drum where the drum wall between the two ends is flexible with the ends interconnected by a plurality of pivoted ribs which are collapsed by radial inward pressure applied by a circling strap.
A further drum is shown in U.S. Pat. No. 1,113,253, the wall of the drum comprising flexible material, the two ends being held in spaced relation by removable spacing bars and retaining the flexible material in a taut condition.
U.S. Pat. Nos. 2,546,452 and 1,768,438 show drums where the walls are composed of a plurality of rigid telescoping rings having interengaging means to limit their relative movements.
These drums however have the disadvantage in that the air space in the drum is either not cylindrical, or has fixed members across the air space and thus these tend to interfere with the vibrations of the air within the drum space.